应用先进光谱技术研究无机离子的环境界面化学

发生在环境界面的吸附-解吸和氧化-还原等反应对于污染物在环境介质间传输、转化以及归趋起着重要的调控作用。传统的研究方法虽然可以在实验室模拟并进而描述污染物环境界面过程,但是不能揭示界面反应机制,限制了对污染物环境界面行为的认识。近二十年来,各种谱学技术(例如X射线吸收精细结构和傅里叶红外光谱等)应用于环境界面反应的研究,推动了这一领域研究的发展,特别是在分子水平研究污染物的环境界面过程。通过现代光/波谱技术原位分析,可以实时获取界面反应的定量与结构信息,从而更准确地判断反应机制,极大促进了对污染物在多介质环境界面迁移转化规律的认识。本文将在概述环境界面化学反应的基础上,针对无机离子在环境界面的反应过程,重点介绍几种关键光/波谱技术(X射线吸收精细结构光谱、傅里叶红外光谱、拉曼光谱、核磁共振谱和穆斯堡尔谱等)在环境界面化学研究中的应用,并展望其在环境界面过程研究中的应用前景。     

ICP-MS的KED模式测定磷酸加王水复溶土壤样品中的二十种金属元素

在研究锗测定时,磷酸先溶解样品,后加入王水复溶,可同时测定锂、铍、钪、钒、铬、钴、镍、铜、锌、锗、钼、镉、钡、镧、铈、钨、铊、铅、钍和铀元素。研究ICP-MS的最佳测量模式、最佳工作状态,以铑为内标校正仪器的漂移。通过选择高、中、低几个国家一级水系沉积物和土壤标准物质随同样品一起实验溶解建立标准曲线,消除消解、分取、定容中带来的不确定误差和基体干扰,选择8个土壤标准物质为实验样本。最终结果表明,该实验方法准确度(ΔlgC)小于0.1,精密度(RSD)小于8%,该方法满足测定要求,适用于地质普通样品的多金属检测。#$NL     

Bestimmung von Fe, Co, Cu, Zn, Se, Rb und Cs in NBS-Ochsenleber, Blutplasma und Erythrocyten durch INAA und AAS

Zusammenfassung Der Gehalt von Fe, Co, Cu, Zn, Se, Rb und Cs wurde in Blutplasma und in Erythrocyten von sechs Normalpersonen mittels der instrumentellen Neutronenaktivierungsanalyse und der flammenlosen Absorptionsspektrometrie (Cu) bestimmt. Zur Überprüfung der Richtigkeit wurde der NBS-Standard 1577, Ochsenleber, verwendet. Die erhaltenen Resultate für Elemente mit höheren Gehalten (Fe, Cu, Zn) liegen weitgehend im Bereich der bisher veröffentlichten Daten. Bei Elementen mit kleineren Gehalten (Co, Se, Rb, Cs) liegen unsere Werte in dem unteren Bereich oder darunter. Für diese Elemente wurden in Blutplasma und in Erythrocyten (hier bezogen auf Trockenmasse) die folgenden Mittelwerte ermittelt: Für Co 0,22 ±0,14 ng/ml, 0,59±0,23 ng/g, für Se 103±18 ng/ml, 401±29 ng/g, für Rb 167±36 ng/ml, 12,1±2,5 g/g und für Cs 0,88±0,18 ng/ml, 13,0±5,7 ng/g.

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Determination of Fe, Co, Cu, Zn, Se, Rb and Cs in NBS Bovine Liver, blood plasma and erythrocytes by INAA and AAS

Summary The content of the above elements has been determined in blood plasma and in erythrocytes of six normal persons by instrumental neutron activation analysis and flameless atomic absorption spectrometry (Cu). The over-all accuracy of these techniques was checked by using the NBS standard 1577, Bovine Liver. The results obtained for elements of higher content (Fe, Cu, Zn) are essentially in the range of other published data. However, our results for elements occurring with lower contents (Co, Se, Rb, Cs) are in agreement with the lowest values of the published data and in some cases they are even significantly below these. For these elements, the following contents have been determined in blood plasma and in erythrocytes (here related to dry weight): for Co 0.22±0.14 ng/ml and 0.59±0.23 ng/g, for Se 103±18 ng/ml and 401±29 ng/g, for Rb 167 ±36 ng/ml and 12.1±2.5 g/g and for Cs 0.88 ±0.18 ng/ml and 13.0±5.7 ng/g, respectively.

Diese Arbeit wurde durch die Deutsche Forschungsgemeinschaft gefördert.Dem Kernforschungszentrum danken wir für den Erlaß der Bestrahlungskosten.Herrn Dr. med. K. Spenger sind wir für die Mitwirkung bei der Blutentnahme und für wertvolle Diskussion dankbar.     

Phosphorescence of aromatic molecules in complexes with crystalline β-cyclodextrin at room temperature

The rate constants for the quenching by oxygen of triplet states of aromatic molecules (naphthalenes-d₈ and-h₈, phenanthrene) forming inclusion complexes with crystalline β-cyclodextrin in water at 290 K are equal to 900–1300 L mol⁻¹s⁻¹. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1450–1453, August, 1997.     

Direct benzylic functionalization of pyridines:Palladium-catalyzed mono-α-arylation of α-(2-pyridinyl)acetates with heteroaryl halides

Herein,we report a Pd-catalyzed mono-a-arylation reaction for pyridine benzylic functionalization.This approach serves as an efficient alternative to synthesize di-heteroaryl acetates in good yields and selectivities.Moreover,the method is applicable to heteroa ryl substrate combinations,and exhibits great functional group tolerance.A streamlined protocol also enables the rapid synthesis of diheteroaryl ketones.The synthetic value was also demonstrated by scale-up experiments.     

Determination of Violet Covasol as a cosmetic dye in water samples by a CPE-Scanometry method

The trace amounts of Violet Covasol as a cosmetic dye was determined by an efficient cloud point extraction-Scanometry(CPE-Scanometry) method. This method has many advantages such as novelty,facility, high speed, sensitivity, low cost and safety. The method is based on the CPE of an analyte from an aqueous solution, diluting the extracted surfactant-rich phase with ethanol, transferring to Plexiglas~cell and scanning of the cells containing the analyte solution with a scanner and measuring the RGB parameters with software written in visual basic(VB 6) media. Parameters impacting the extraction efficiency such as p H of the system, the concentration of surfactant, equilibration temperature and time were optimized. Detection limit(DL), relative standard deviation(RSD) and linear range for the proposed method are 0.026, 0.71 and 0.16–6.6 μg m L ~(-1)respectively. The method was successfully applied for the determination of Violet Covasol dye in several water samples, including a water sample containing the dye as a tracer(to investigate subsurface water movement).     

Electrocatalytic Oxidation and Simultaneous Determination of Uric Acid,Xanthine, Hypoxanthine and Dopamine Based on β-Cyclodextrin Modified Glassy Carbon Electrode

A novel covalently modified glassy carbon electrode with β-cyclodextrin was prepared via electropolymerization technique for the simultaneous determination of uric acid(UA), xanthine(XA), hypoxanthine(HX) and dopamine(DA). This new electrode presented an excellent electrocatalytic activity towards the oxidation of UA, XA, HX and DA by cyclic voltammetry(CV) method. The oxidation peaks of the four compounds were well defined and had the enhanced peak currents. The separation potentials of the oxidation peaks for DA-UA, UA-XA and XA-HX were 150, 390 and 360 mV in CV, respectively. By means of differential pulse voltammetry(DPV) method, the calibration curves in the ranges of 10-225, 5-105, 10-170 and 5-150 μmol/L were obtained for UA, XA, HX and DA, respectively. The lowest detection limits(S/N=3) were 5, 1.25, 5 and 1.5 μmol/L for UA, XA, HX and DA, respectively. The practical application of the modified electrode was demonstrated by the determination of DA in hydrochloride injection and UA, XA, HX in human urine samples.     

Synthesis and cytotoxic activity of 3-phenyl-4-substituted-β-carbolines

A new class of 3-phenyl-4-substituted-β-carbolines via iodine-mediated electrophilic cyclization as key step were synthesized and their inhibitory activity against three tumor cell lines was evaluated in vitro.It was found that some of the tested compounds showed better cytotoxicity against HeLa and MCF-7 cells than harmine.     

DC discharge in an alternating magnetic field as excitation source in emission spectroscopy

Summary The experimental study of the behaviour of a dc discharge in an alternating magnetic field is described. The lower electrode (anode) is a horizontally located chamber electrode. The alternating magnetic field causes oscillations along the lower electrode axis so that the oscillating arc can equably heat the anode. The axial distribution of the spectral line intensities for lead, bismuth, mercury, cadmium, tin and antimony is investigated. The intensity distributions are studied for near-to-cathode and near-to-anode regions of the discharge. The detection limits obtained for pure conditions show that the effects of chamber electrodes and of double arc could be achieved by means of a relatively simple technique.

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Ein Gleichstrombogen im Wechselmagnetfeld als Anregungsquelle in der Emissionsspektrographie

Zusammenfassung Untersuchungen über das Verhalten eines Gleichstrombogens in einem Wechselmagnetfeld werden beschrieben. Die untere Elektrode (Anode) ist eine horizontale Kammerelektrode. Das Wechselmagnetfeld verursacht Bogenschwingungen entlang der Achse der unteren Elektrode und ermöglicht dadurch deren gleichmäßige Heizung. Die axiale Verteilung der Linienintensitäten von Blei, Bismut, Quecksilber, Cadmium, Zinn und Antimon wurde für beide Elektroden untersucht. Die berechneten Nachweisgrenzen zeigen, daß die Wirkung der Kammerelektrode und des Doppelbogens mit einfachen Mitteln erreicht werden kann.

     

中文化学名词醇醛酮醚酯之由来

1932年民国教育部颁布的《化学命名原则》为中文化学名词确立了统一的标准,并对于“元素及化合物定名取字”提出“取字应以谐声为主,会意次之,不重象形”的定名总则。它确立的中文化学名词醇、醛、酮、醚、酯是意译名,这似乎与其音译为主的命名原则相悖。本文讨论了醇、醛、酮、醚、酯的各种历史译名,并分析了它们被《原则》采纳的原因。     

Reconstruction of the surface layer of platinum group metals in the thermal treatment in various gases and propane hydrogenolysis

The enrichment with ruthenium of the surface layer of a Pd−Ru alloy tube during the propane hydrogenolysis was observed. Metal particles immobilized within carbonaceous deposits and filamentous crystals of the metals with a carbon cover are formed on the Rh and Ir wires. Thermal treatment in gases free of carbon compounds does not cause such a deep reconstruction. The deep reconstruction occuring during the propane hydrogenolysis is the stronger, the greater the amount of carbon this metal dissolves. Dedicated to the memory of Academician M. E. Vol'pin timed to his 75th birthday. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1100–1103, June, 1998.     

单体结构对紫外光固化氧阻聚影响的研究

利用光量热仪(UV-DSC)对单体TMPTA以及不同乙氧基化的TMPTA单体进行了紫外光固化实验。通过比较空气气氛和氮气气氛下光固化速率增长最快时的时间t_amax的差异来评价光固化初期氧阻聚的大小。考察了单体中乙氧基上的α-H的数量以及单体的流动特性对氧阻聚的影响。结果表明,提高单体中乙氧基的数量能减小光固化过程中的氧阻聚,氧阻聚的大小与单体中α-H的数量以及单体的黏度有关.     

New methods for the determination of elements in trace amounts

Summary Recent methods for the determination of elements on trace amounts are discussed, which have been mainly developed in the author's laboratories. The review comprises the following sections: reagents and reactions, charge transfer reactions, candoluminescence, molecular emission spectroscopy in flames, enzymatic methods, gas-liquid chromatography of metal chelates, mass spectrometry of metal chelates.

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Neue Methoden zur Bestimmung von Elementen in Spurenmengen

Zusammenfassung Verfahren werden besprochen, die in den letzten Jahren hauptsächlich in den Laboratorien des Autors entwickelt wurden. Der Überblick umfaßt folgende Kapitel: Reagentien und Reaktionen, Charge-Transfer Reaktionen, Candoluminescenz, Molekular-Emissions-spektroskopie in Flammen, enzymatische Methoden, Gas-Flüssigkeits-Chromatographie von Metallchelaten und Massenspektrometrie von Metallchelaten.

Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9. 1972 in Heidelberg, Germany.     

Further understanding of fat biology: Lessons from a fat fly

Obesity is a leading risk factor for insulin resistance, hypertension, hyperlipidemia, and cardiovascular complications, collectively referred to as metabolic diseases. Given the prevalence of obesity and its associated medical problems, new strategies are required to prevent or treat obesity and obesity-related metabolic effects. Here we summarize contributors of obesity, and molecular mechanisms controlling adipogenesis from studies in mammalian systems. We also discuss the possibilities of using Drosophila as a genetic model system to advance our understanding of players in fat biology.     

Accumulation of argpyrimidine, a methylglyoxal-derived advanced glycation end product, increases apoptosis of lens epithelial cells both in vitro and in vivo

The formation of advanced glycation end products (AGEs) has been considered to be a potential causative factor of injury to lens epithelial cells (LECs). Damage of LECs is believed to contribute to cataract formation. The purpose of this study was to investigate the cytotoxic effect of AGEs on LECs both in vitro and in vivo. We examined the accumulation of argpyrimidine, a methylglyoxal-derived AGE, and the expression of apoptosis-related molecules including nuclear factor- kappaB (NF-κB), Bax, and Bcl-2 in the human LEC line HLE-B3 and in cataractous lenses of Zucker diabetic fatty (ZDF) rats, an animal model of type 2 diabetes. In cataractous lenses from twenty-oneweek- old ZDF rats, LEC apoptosis was markedly increased, and the accumulation of argpyrimidine as well as subsequent activation of NF-κB in LECs were significantly enhanced. The ratio of Bax to Bcl-2 protein levels was also increased. In addition, the accumulation of argpyrimidine triggered apoptosis in methylglyoxal- treated HLE-B3 cells. However, the presence of pyridoxamine (an AGEs inhibitor) and pyrrolidine dithiocarbamate (a NF-κB inhibitor) prevented apoptosis in HLE-B3 cells through the inhibition of argpyrimidine formation and the blockage of NF-κB nuclear translocalization, respectively. These results suggest that the cellular accumulation of argpyrimidine in LECs is NF-κB-dependent and pro-apoptotic.     

酸敏感型嵌段共聚物mPEG-acetal-PIB的合成、表征及用于构筑水凝胶敷料

利用点击化学(“Click”)反应, 成功制备了一种通过酸敏感缩醛基团键合的两亲性嵌段共聚物, 聚乙二醇单甲醚-acetal-聚异丁烯(简写为mPEG-acetal-PIB). 通过核磁共振氢谱(¹H NMR)、红外光谱(FT-IR)和凝胶渗透色谱(GPC)对聚合物的结构、分子量及分子量分布进行表征. 利用芘荧光探针法、动态激光光散射(DLS)和透射电子显微镜(TEM), 研究共聚物在水溶液中组装的临界聚集浓度(CAC), 胶束的粒径大小、分布以及形貌. 利用DLS跟踪测试聚合物胶束在酸性条件下的粒径变化, 验证mPEG-acetal-PIB的酸敏感性质. 随后, 在体系中引入α-环糊精(α-CD), 诱导形成超分子水凝胶. 利用X射线衍射(XRD)分析PEG与α-CD的包结络合作用, 流变仪测试水凝胶的凝胶化时间和黏弹性. 通过体外细胞毒性试验(MTT法)证明嵌段共聚物mPEG-acetal-PIB及水凝胶均具有良好的生物相容性. 这种水凝胶能够保持创面湿润, 具有温和的冷却作用, 并且由于其带有酸敏感基团, 能够在偏酸性环境降解, 减少炎症发生率, 在水凝胶创伤敷料中具有潜在的应用.     

Copper-catalyzed α-selective C-H trifluoromethylation of acrylamides with TMSCF3

A copper-catalyzed α-selective C-H trifluoromethylation of acrylamides with TMSCF₃ is described. A wide range of arenes and heteroarenes at the β-position of acrylamides are compatible with the reaction, affording the corresponding (E)-trifluoromethylated products in moderate to good yields. The reaction proceeded fast and can be completed within 30 min.     

新型桃金娘烯醛基双酰胺-噻二唑化合物的合成及其抗真菌活性

以α-蒎烯为起始原料,经氧化制得桃金娘烯酸（3）;脂肪族二酸在POCl₃作用下与氨基硫脲经脱水环合制得脂肪族双噻二唑（4a~4h）; 4a~4h分别与3经脱水反应合成了8个新型的桃金娘烯醛基双酰胺噻二唑化合物（5a~5h）,其结构经¹H NMR, ¹³C NMR, IR和ESI-MS表征。抗真菌活性测试结果表明,在用药量为50 μg·mL^-1时,5a~5h对黄瓜枯萎病菌、花生褐斑病菌、苹果轮纹病菌、番茄早疫病菌和小麦赤霉病菌均有一定的抑制作用,其中桃金娘烯醛-辛二酸基双酰胺-噻二唑(5f)对苹果轮纹病菌的抑制率为60.3%,桃金娘烯醛-丁二酸基双酰胺-噻二唑(5b)和桃金娘烯醛-癸二酸基双酰胺-噻二唑(5h)对小麦赤霉病菌的抑制率分别为52.8%和54.4%。